a(n) = (n^2+1)*(4*n^2+1)*(4*n^2+3).

Terms

a(0) =3a(1) =70a(2) =1615a(3) =14430a(4) =74035a(5) =270478a(6) =788655a(7) =1960150a(8) =4326595a(9) =8714550a(10) =16321903a(11) =28815790a(12) =48442035a(13) =78146110a(14) =121705615a(15) =183874278a(16) =270537475a(17) =388879270a(18) =547560975a(19) =756911230a(20) =1029127603a(21) =1378489710a(22) =1821583855a(23) =2377539190a(24) =3068275395a(25) =3918761878a(26) =4957288495